codec quality ranking

[akrako1]

With all the new codecs floating around these days, I'm in need of a quick quality guide. At the same bitrate, which codecs look the best?

Here's my scenario, I'm looking to download a bunch of episodes of a show. What is the best video quality I can get for the SAME FILE SIZE? ie. which version should I download to get the best visual quality? I see many different 'rips' of things posted in many different formats/codecs. Need to know how they rank. I'm don't care about encoding time, just the resulting playback quality.

I can start us off with the simplest... Divx is higher quality then MPEG-2 (at the same bitrate of course)

(best)

Divx
Mpeg-2

(worst)

How does xVid compare with Divx? about the same? Where would x264 come in? Since it's newer, I'd assume it's higher quality then Divx. WMV9? How about H264? Better then x264? any other new ones?

Remember I'm talking about the SAME BITRATE so the same resulting file sizes. I'm assuming that resolution is constant as well.

My guess for a quality hierarchy would be:

H264 (MPEG-4 Part 10)
x264 (MPEG-4 AVC)
Divx (MPEG-4 Part 2)
xVid (MPEG-4)
Mpeg-2
Mpeg-1

Thoughts?

[guns1inger]

Close enough, although at low bitrates, mpeg-1 often produces better results than mpeg-2 (sub 1 - 2 kbps range)

That said, codec choice is only one part of the equation. You can use the best codec in the world, and get a really bad encode out of it if you don't know what you are doing. 70% of downloadable material is ripped and encoded by people who fall into this category. They use substandard tools (WinAVI, anyone) or they use the right tools, but very badly. You can encode using AVC at a good bitrate, and still screw it up by using deinterlacing badly or screwing up the aspect ratio or framerate.

So honestly, if you choose to download rips, rather than purchase and encode yourself, you get what you pay for. You can't choose on codec alone as it tells you nothing of the actual quality.

[akrako1]

ok, also assuming that the encoder knows mostly what they're doing, and they don't screw up anything, how would they rank then? just trying to reduce macroblocking, etc.

[guns1inger]

Assuming everything else is equal (resolution, bitrate, audio etc), pretty much as you have them. You also need to hope that the bitrate chosen is actually adequate, and not some arbitrary CD capacity based sizing, and that the encoder is a good one. I have seen some very shoddy stuff produced by one encoder, when a longer movie has been squeezed into the same space at a much higher quality by using a better encoder, or by encoding with 2 passes instead on one etc. I have seen Xvid encodes that are equal to AVC encodes done at the same bitrate, simply because the person doing the encoding used a better encode and set it up correctly.

Rank codecs all you like, but they are not the be-all and end-all of the quality equation.

[MysticE]

I'm looking to download a bunch of episodes of a show

Seems like about 99% of them will be Xvids anyway.

[Nelson37]

Your assumption that resolution is constant is just about as valid as assuming that the encoder knows what they are doing, which is to say, not at all. Not even a little bit. Download 10 vids, you will likely find at least 6 to 8 different resolutions. Also, most likely, 8 or 9 piles of crap with one or two halfway decent.

A well-cooked hamburger is superior to a burnt steak. It is probably easier to screw up a steak than it is a hamburger. A screwed up hamburger is more likely to be discarded and a new one done, a screwed up steak is less likely to be thrown out. I am comparing this to production time, the newer codecs take many hours to do and will most likely be distributed whether they are any good or not. Faster encodes more likely to be re-done.

Better video looks better. Crappy video looks crappy. I would suggest that MPG2 or Xvid is more likely to be decent simply because these tools have been around longer.

"Keeper" quality on downloaded vids runs about 10%, IMO.

Since very few are playable on a standalone, PC playback is almost mandatory, which makes de-interlacing desireable, and this is a major area where most people screw-up.

[lordsmurf]

Your assumption that resolution is constant is just about as valid as assuming that the encoder knows what they are doing, which is to say, not at all. Not even a little bit. Download 10 vids, you will likely find at least 6 to 8 different resolutions. Also, most likely, 8 or 9 piles of crap with one or two halfway decent.

A well-cooked hamburger is superior to a burnt steak. It is probably easier to screw up a steak than it is a hamburger. A screwed up hamburger is more likely to be discarded and a new one done, a screwed up steak is less likely to be thrown out. I am comparing this to production time, the newer codecs take many hours to do and will most likely be distributed whether they are any good or not. Faster encodes more likely to be re-done.

Better video looks better. Crappy video looks crappy. I would suggest that MPG2 or Xvid is more likely to be decent simply because these tools have been around longer.

"Keeper" quality on downloaded vids runs about 10%, IMO.

Since very few are playable on a standalone, PC playback is almost mandatory, which makes de-interlacing desireable, and this is a major area where most people screw-up.

Perfect answer.

Most downloads look like garbage, with settings all over the place. Lack of knowledge is why everything looks so bad. Many of them are stubborn too, unwilling to learn better methods. Lots of audio sync errors on downloaded files, at least 25% or more in my observations.

[wolf2009]

x264 is not a codec . It is an encoder for encoding to H.264 .

[meldavid]

I've been testing different tools and codecs a bit lately cause I just bought a stand-alone and want to get my fave movies on there. I've been using frame size of 640 x 272 for 2:35:1 films and a bitrate of 2500 kbps for movies like LOTR, and about 1600 kbps for comedy/drama.

I've used Handbrake, VirtualDub, MPEG Streamclip and the Xvid, DivX, and libavcodec codecs.

From my tests I think I prefer the ffmpeg (libavcodec) codec in Handbrake (can't seem to find a way to use this codec in VirtualDub or Mpeg Streamclip though). It had the less noticeable artefacts from normal viewing distance on a 40" LCD.

DivX to me looked more grainy compared to the other codecs but only up close. I would rate it second to ffmpeg.

When I use Xvid, the quality is fine, but occasionally I get this sudden gamma or brightness shift from one frame to the next - which is not a big change - but which can be noticeable in scenes when not much action is happening. I don't know what causes it as some of the stuff I've downloaded that have been encoded with Xvid don't have it. I don't know if there are any options or switches to prevent that.


H.264 takes too long to encode and is not supported by my stand-alone anyhow. Also Handbrake doesn't allow to keep the AC3 rip with H.264.

Hard disk space is getting so cheap so I prefer faster encode times using higher bitrates to keep more of the quality.

All this testing was done on Windows PCs using VirtualDub or Mac using Handbrake. I wanna do some testing with ffmpegX now.

Deinterlacing is something I've been mucking about with too. The trickiest to deinterlace is pron, because of the high action, haha. So far I think the Smart Deinterlacer for Virtualdub is best so far but I'm still not quite satisfied with the results. I haven't tested ffmpegX's deinterlace filter yet.

I got to say though, encoding is hard work. Kudos to those of you who get it right!

[guns1inger]

There is a version of Handbrake avilable for Windows, but frankly I have found it's results to be very underwelming, especially compared to something like AutoGK for Xvid/Divx encoding.

[meldavid]

Ooh I should give AutoGK a go. I just found Handbrake really easy to setup (specially the Mac version) and results were satisfactory for me on big-budget DVDs as long as I picked the Mpeg 4 encoder in Windows or FFmpeg encoder on Mac.

If I wanted to use Smart Deinterlace in VDub, I've had to run DGIndex to create .d2v files that can be opened in VDub via AVISynth. But in VDub I can only use the Xvid or DivX codec.

...

Well, ffmpegX is no good for me right now. It has glitchy video and I can't encode with Trellis Quatization and 4 Motion Vectors turned on. I am running Leopard though so it may not be compatible yet.

[guns1inger]

The latest vdub, or vdubmpeg2 can open mpeg-2 or VOB files natively